Method and apparatus for photographic image production



P. 8. SMITH Oct. 17," 1939.

METHOD AND APPARATUS FOR PHOTOGRAPHIC IMAGE PRODUCTION Filed July 11, 1936 8 Sheets-Sheet 1 INVENTOR Pl/L w 37/44 46 Y 5/7/59.

ATTORNEY P. S. vSMITH Oct. 17, 1939.

IETKOD AND APPARATUS FOR PHOTOGRAPHIC IMAGE PRODUCTION Filed July 11, 1936 8 Sheets-Sheet 2 Oct. 17, 1939.

P. 8. SMITH 2,176,108

METHOD AND APPARATUS FOR PHOTOGRAPHIC IMAGE PRODUCTION Filed July 11, 1956 8 Sheets-Sheet 3 AT ORNEY Oct. 17, 1939. P. 5. SMITH 2,176,108

METHOD AND APPARATUS FOR PHOTOGRAPHIC IMAGE PRODUCTION Filed July 11, 1936 8 Sheets-Sheet 4 INVENTOR P/y/z/P STANLEY 5/1/77,

BY 11mm M NEY 0a. 17, 1939. P. 5. SMITH 2,176,108

METHOD AND APPARATUS FOR PHOTOGRAPHIC IMAGE PRODUCTION ATTORNEY P. 5. SMITH Oct. 17, 1939.

METHOD AND APPARATUS FOR PHOTOGRAPHIC IMAGE PRODUCTION Filed July 11, 1936 8 Sheets-Sheet 6 INVENTOR Pym/, Smut- 5/7.

A TORNEY P. 5. SMITH Oct. 17, 1939.

METHOD AND APPAfiATUS FOR PHOTOGRAPHIC IMAGE PRODUCTION Filed July 11, 1936 8 Sheets-Sheet 8 INVENTOR Pl/L/P Sun 45v S/v/r/n ATTOR N EY Patented Oct. 17, 1939 UNITED STATES PATENT OFFICE METHOD AND APPARATUS FOR PHOTO- GRAPHIC IMAGE PRODUCTION 37. Claims.

This invention relates to photographic reproduction and more particularly to improvements over the methods and apparatus disclosed in United States Letters Patent Nos. 1,927,925 and 2,025,731,0f Ludwig M. Dieterich; inrthose patents aredescribed methods and apparatus for producing photographic pictures having the effect of relief or depth.

One. of the dominant aims of this invention is to provide a method and apparatus of the abovementioned character in which control of lens movements may be achieved in a more facile,

, more flexible, and more advantageous manner than has heretofore been proposed and in general to improve upon the methods, apparatus, and results disclosed in the aforesaid Dieterich patents. Another object is to provide a lens mounting or mountings and a method and apparatus'for moving the latter that will dependably avoid possible deficiencies in known methods or apparatus for effecting lens movement. Another object is to provide a method and apparatus for controlling the movement of a lens or lenses that will be capable of precision and simplicity of control and of wide range of flexibility.

Another object is to provide a dependable and. easily operable method and apparatus for testing or determining a setting or action of one or more movable lenses of a lens system. Another object is to provide, in a method and apparatus of the type disclosed in the said Dieterich patents, a simple yet precise and accurate method and apparatus for determining and testing the range of movement to be given to a movable lens or lenses 5 of a lens system andto test and determine the action of such setting or movement.

- Another object is to provide a lens system having one or more movable lenses capable of greater accuracy and speed of movement and greater flex- 4Q ibility of change in speed or range of movement thereof than has heretofore been possible.

Another object isto improve in general upon known methods and apparatus for achieving, in photographic recording or reproduction of objects 5 or scenes, the effect of relief or depth. Another object is in general to provide an improved method and apparatus. for achieving improved photography having the effect of relief or depth and more particularly to provide such improved meth- 5 0d and apparatus that will be well adapted to meet the varying conditions and requirements met with in practice, particularly in motion picture work, and to provide, particularly in the latter field, a wide range of accurate and dependable control and action, depending upon the various and different conditions met with or efiects that are desired to be achieved. Another object is to provide 'an apparatusof the above-mentioned character which will be compact, durable, easily mobile, and well adapted, particularly as to such 5 matters as ease and speed of adjustment, control, testing, or the like, to meet the peculiar and varied requirements of photography in general and motion picture photography in particular. Other objects will be in part obvious or in part 10 pointed out hereinafter. v

The invention accordingly consists in the features of construction, combinations of elements, arrangements of parts, and in the several steps and relation and order of each of the same to one 15' or more of, the others, all as will be illustratively described herein, and the scope of the application of which will be indicated in the following claims.

In the accompanying drawings in which are shown several illustrative embodiments of the 20 invention,

Figure l is a plan view on a small scale of a camera, illustratively a motion picture camera;

.Flgure 2 is a side elevation thereof;

Figure 3 is an end elevation as seen from the 25 right in Figure 1;

Figure 4 is a perspective view on a still smaller scale of such a motion picture camera illustrating also the manner in which certain of the control apparatus is associated therewith;

Figure 5 is a central vertical sectional view, with'certain parts broken away or omitted, and on an enlarged scale, substantially as seen along the line 55 of Figure 1, or the line 55of Figure 3, showing a preferred form of lens mounting and actuating mechanism;

,Figure 5 is a. detached view indicating a possible form of step-by-step film-advancing mechanism;

Figure 6 is an elevation, as it would be seen 40 along'the line 6-4 of Figure 5, of part of the structure carrying the lens mounting and lensmoving means;

Figure '7 is an elevation of part of a magnetic field structure;

Figure 8 is an elevation as seen from the left of Figure 7;

Figure 9 is a plan view of a vibratable support for the lens mountings;

Figure 10 is an elevation illustrating a possible modified form of a vibratable support for a lens mounting;

Figure 11 is a view on an enlarged scale, as seen from the right in Figure 2 or from the front of Figure 3, certain parts of the camera per se being omitted and certain parts being shown in elevation and others in section to show the construction more clearly;

Figure 12 is an electrical diagram of the circuit arrangements and electrical system for achieving certain controlling and testing actions and operations;

Figure 13 is a central vertical sectional view, like that of Figure 5, with certain parts broken away or omitted, and on an enlarged scale, substantially as seen along the line 5-5 of Figure 1 or the line 5-5 of Figure 3, showing a preferred form of lens system with its mounting and actuating and related. mechanism, and

Figure 14 is a diagrammatic representation, like that of Figure 12, of the circuit and other arrangements for effecting certain controlling, operating, and testing operations of the lens system of Figure 13.

Similar reference characters refer to similar parts throughout the several views in the drawings.

As conducive to a clearer understanding of certain features of this invention, it might here be noted that, while I have shown the illustrative embodiments of my invention and described them hereafter as particularly adapted for motion picture photography I do not intend to be limited to the latter and hence it is to be understood that my invention contemplates and includes still or like photography, as well as, generally, the production of images of any scene, object, or the like. Accordingly, and turning now first to Figures 1-4, I have there shown a camera of the motion picture type; it comprises a casing 3|) mounted as later described upon a base or frame 3|, the latter being mounted upon any suitable support diagrammatically indicated in Figure 4 at 32. The camera casing is provided as shown in Figure 4 with suitable film reels or holders 33 and 34 for coaction with the film 35, the latter being in the usual strip form, and being fed through suitable film-driving mechanisms (not shown) including the usual shuttle mechanism, shutter, or the like, as is now well known in the art and examples of which may be found in Dieterich Patent 2,025,731. The camera casing 30 is provided with any suitable source of driving power, such as a hand crank, motor, or the like (not shown) to achieve the desired operation of the various film handling and coacting mechanisms, such as those above-mentioned. By way of illustration, however, I have shown in Figures 1, 2 and 4, as illustrative of such a source of driving power a hand crank 36.

In so far as the above-described parts are concerned, they may take any suitable or appropriate form and they may be like those embodied in wellknown commercial forms of motion picture cam eras. Preferably, the camera is so constructed, also as is well-known, as to have the casing 33 slidable transversely relative to the base 3|, the latter having transverse ways 31, 38 for guiding the casing transversely. Also, the right-hand portion of the base 3l, as seen in Figures 1, 2 and 4, has an upright hollow casing part or standard 40 with respect to which the casing 30 is likewise slidable.

Upon the front of the upright standard 40 (Figuresl and 2) is rotatably mounted a disklike plate 4| suitably provided with means for holding a suitable number of lenses or lens systems, illustratively four in number, as shown in Figure 3 at 42, 43, 44, 45, plate or lens support 4| being carried for rotary movement by a stud shaft 46. The lenses or lens systems 42, 43, 44, may thereby be selectively positioned with respect to the aperture, shutter and film of the camera and may be of any desired or suitable construc tion and preferably different action, excepting that at least one of them, illustratively the lens system 42, embodies certain features of my invention and hence in Figure 3 it is the lens system 42 that is shown positioned for having the film 35 exposed therethrough, the camera casing 30 being for such purposes shifted into the position shown in Figure 1. The casing 30, when shifted downwardly along ways 31, 38, to its other extreme position, permits the operator to sight through the selectively positioned lens system and to witness or inspect the scene or object which is -about to be photographed. Casing 30 when given an intermediate position alines a casing extension 46 (Figures 1 and 3) with the optical axis of the selected lens system and likewise alines with the latter an aperture 41 (Figure 3) to permit the entry into the casing part 46 of light rays from the lens system, the casing part 46 containing certain light-sensitive testing devices as later described in detail.

Considering now more in detail the lens system 42, reference may first be made to Figure 5 in which the lens system 42 is shown in enlarged vertical central cross-section, being enclosed or encased, with certain related mechanism later described, in a cylindrical casing 50 carried in any suitable way by the lens-carrying plate 4|, to which also the lens system and related parts are preferably secured in any suitable way. In Figure 5 the rotatable plate 4| is shown only fragmentarily and it is, of course, provided with a suitable opening to which is related in any suitable way a separate aperture member 5| adjacent to which is mounted a suitable shutter diagrammatically indicated at 52 to control the exposure through the lens system and through the aperture 5| of the film 35, the latter being indicated diagrammatically in Figure 5. Any suitable means may be employed to advance the film to present frames thereof successively into the image plane for successive exposure by the shutter and it may take the form of that shown in Figure 2 of Dieterich Patent No. 2,025,731, the pertinent parts of which are reproduced in Figure 5 herein. In the latter a portion of the film 35 is shown in relation to the apertured shutter 52, the latter being driven in any suitable way as by the shaft 52 comprising a suitable member to engage in the holes in the strip film for moving the latter, periodic movement being achieved in any suitable way as by a cam 52 on the shaft 52 having suitable connections indicated at 52 with the filmengaging member 52 The lens system 42, according to one embodiment thereof, may comprise lenses 53, 54 and 55 constructed individually in any suitable way and preferably and illustratively constructed to constitute a lens system of the type shown in Figures 2, 3 and 4 of Dieterich Patent No. 1,927,925; thus, lens 53 may correspond to lens 20 of the patent, lens 54 may correspond to lens 2| of the patent, and lens 55, though shown in Figure 5 as a single lens, may comprise the composite lens 22-23 of the said Dieterich patent; these three lenses or lens groups are to be given certain movements relative to each other and relative to the image or film plane represented diagrammatically by the film or sensitized camera element 35 in Figure 5, and for a detailed explanation of the construction of this lens system and of the above-mentioned relative movements, reference is to be had to the said Dieterich Patent No. 1,927,925. In the latter are described various ways in which such a lens system may be actuated to achieve upon the sensitized camera element or film an infinite number of images of the scene or object, each, however, corresponding to a different focus or plane of sharpness and all of the recorded images being of the same size and registering throughout, thereby giving therecorded effect of relief or depth in the scene or object photographed.

Where the lens system is of the just described Dieten'ch type, I prefer to provide separate and separately movable mountings for the individual lenses or lens groups and also separate moving means for these mountings; since in general these mountings and moving means are substantially the same for each lens or lens group, one of them will be described in detail and the others described only generally.

Thus, considering the lens 53 of Figure 5, it is supported in any suitable way, as by threaded clamping rings (not shown) in a cylindrical carrier 56, the latter being preferably of brass and having its axis coincident with the optical axis of the lens 53. The lens carrier 56 is secured to a diaphragm-like spring support 51, in any suitable manner, which is disk-like in shape, made of a suitable spring material, preferably metallic and preferably non-magnetic. 'Illustratively, it may be made of sheet spring bronze, and in form and shape it may take that better shown in Figure 9; by way of further illustration, it may be made of non-metallic material, such as Bakelite in sheet form, preferably with a cloth base.

Referring now to Figure 9, the spring lens support 5! will be seen to be in the form of a disk of substantial diameter, having a central round opening 58 to the periphery of which the lens mounting 56 (see Figure 5) may be mounted or secured in any suitable manner, as is illustrated in Figure 5.

About the opening 58 (Figure 9) the spring mounting preferably has a substantial ring-like area or unbroken portion 59 to which is secured, as by screw or the like, an annular or ringshaped armature 60 (Figure 5) of a suitable magnetic material, such, for example, as permalloy. Preferably, the armature 60 is physically and magnetically held in spaced relation from the portion 59 of the spring mounting 51, by an interposed ring or collar 6| made of brass.

The non-magnetic collar BI and the armature 66 are preferably secured together coaxially as by rivets (not shown) and the resultant unit mounted on the mounting 51 so that its axis is coincident with the optical axis of lens 53. This mounting may be achieved in any suitable manner, illustratively as by screws 63 (Figure 9) at appropriately spaced points threaded intothe armature and by rivets 62 preferably alternated with the screws 63. By way of loosening the screws 63 in course of assembly the armature may be allowed to find its magnetic alinement and may then be anchored in position by the rivets 62 as well as screws 63.

The armature 60 carries an energizing coil 64 wound and terminated in any suitable manner and in a like way is supported upon and insulated from the outer cylindrical periphery of the armature 60, the latter being preferably p-eripherally grooved to receive the winding 64.

Winding 64 and armature 60 are made to coact with certain parts later described in detail.

Referring again to Figure 9, the disk-like lens support 5! has an outer substantially unbroken or ring-like portion 65 which is joined to the inner ring portion 59 by a suitable number of uniformly distributed arms 66, this configuration of the sheet-like support 51 being achieved, for example, by stamping or punching operations, which cut out openings 61 in the disk to provide these yieldable or spring-connecting arms 66. The outer ring portion 65 of the lens support 51 is provided with suitably and uniformly spaced holes 68 whereby, and with other parts later described, the outer ring portion 65 may be securely anchored against movement so that the inner ring portion 59, with its armature 60 and coil 64, may move axially because of the springiness of thev material of the member 51 and particularly because of the springiness of the connecting arms 66.

The latter, moreover, when shaped as shown in Figure 9, provide virtually three axes about which the arms or portions thereof may bend relative to each other, and in Figure 9 these axes are shown, with respect to one of these connecting arms at A--A, B-B and C-C. Thereby the arms 66 insure a nice resiliency or yieldability of mounting of the armature 60 and of the lens mount 56 (Figure 6) and the uniformity of distribution, construction, and action of the arms 66 insure that any movement of the lens 53 is always a true axial movement and that the lens 53, as it moves axially, does not partake of any tilt with respect to the optical axis of the lens system with which its own optical axis is coincident and must, therefore, remain coincident throughout movement.

In Figure 10 is shown and indicated by the reference character 5'! another possible form or shape which the spring lens support 57 just described may assume; here there are againpro- Vided inner and outer annular or ring-shaped portions shown at 59 and 65 and by providing uniformly distributed curved slots 10'H, IO-ll, etc., the central ring portion 59 with the armature 60 and lens mount 56 becomes supported by composite or bifurcated arms 12 which, in yielding, may bend about axes F-F, G-G and HH. Here again, the spring disk-like support may be easily fabricated as by stamping.

Recurring to Figure 5, the outer ring portion 65 of the spring support 51 is seated against the annular face of a recess 13 in a relatively heavy annular or ring member 14 made preferably of a suitable non-magnetic material like brass and it is clamped and thus securely anchored against this annular face 13 by a clamping ring 76 also preferably made of non-magnetic material such as brass. The non-magnetic ring member 14, is cut away as at 11 throughout its side face so as to clear the free or unrestrained portions of the spring support 5'! and to give such portions freedom, of vibrating or oscillating movement as the connecting arms above-mentioned in connection with Figures 9 and 10 are made to yield, and within the circle of largest diameter of this cut away portion 11, the ring member M is shaped or cut out rectangularly to form a rectangular seat 18 shown in Figure 6. Seat 78 has fitted into it and secured thereto in any suitable way a field structure made of magnetic material, such as permalloy and shaped as is better shown in Figures 7, 8 and 5.

This field structure comprises a part 80 and a companion part 8| (Figure 5). Part has an upstanding main portion 82 (Figures 5, 7 and 8) that is rectangular in shape and thus reecivable within the above-mentioned seat 18 (Figures 6 and 5) and at its upper and lower ends has horizontal extensions 83, 34 from which extend, in a direction parallel to the main portion 82, portions and 80, respectively; the latter portions fall short of meeting each other (see Figure 8) and, furthermore, have their juxtaposed faces arcuate in shape, as at Bl and 88, respectively (Figures 7 and 8), the radius of curvature of these juxtaposed faces 81, 80 being somewhat greater than the radius of the outer cylindrical face of the armature 60 (see Figure 5) The main portion 82 of the member 80 has a central round aperture therein.

In this aperture 90 is fitted and secured in any suitable way the above-mentioned companion field piece ill (see Figure 5), the latter being annular or ring-shaped and rabbeted to interfit with. the apertured main portion 82 of the member 80, as shown in Figure 5.

The largest or outside diameter of the field piece 8| is less than the inside diameter of the ring-shaped armature 60 and thus forms with the arcuate pole faces 81-88 (Figures 7 and 8) a substantially annular air gap into which, as shown in Figure 9, the armature 60 extends and is received. The inside diameter of field piece BI is somewhat larger than the outside diameter of the lens mounting 56 (see Figure 5) and thus there is provided appropriate clearance for the axial movement of the lens mounting 58.

To set up a magnetic field across the air gaps of the core or field structure 80-8I, I provide a winding 9i (Figure 5) of annular form and extending about the field part 8|; this winding when energized sets up a magnetic field or flux whose circuit (or circuits) includes the core structure 80-8I and the air gaps in which extends the armature 60. Preferably, the field winding 9| is energized with direct current of a given value and hence there extends across the air gaps a magnetic field or flux of a corresponding value, that flux being, like the current producing it, uni-directional, and in such case I energize the armature winding 64 by an alternating current of appropriate frequency, thereby producing a magnetic field or flux which, like the current producing it, is also alternating. Accordingly, with every reversal in the current in and hence flux produced by the armature winding '64, change in direction of movement of the armature and hence of the lens 53 takes place, and the extent or ployed, the rate of oscillation of the lens 53 may be determined as is desired.

- The remaining lenses of the lens system of Figure 5 are mounted and moved in a substantially similar way. Thus, lens 54 is carried in a lens mount 92 supported by a spring support 93, the latter carrying the armature 94 by way of the spacer ring or collar 95and being seated in a recess 96 in a ring member 91 and held thereagainst by a clamping ring 98. The non-magnetic ring member 91 has a substantially rectan gular opening I00 in it to receive the field or core structure IOI--I02, the latter having an energizing winding I03, illustratively energized by direct current, and the armature 94 having a winding I04 illustratively energized by alternating current. These various parts are similar in construction to those earlier above described in connection with lens 53 and the resultant two unit assemblies, carried by the ring members I4 and 91, respectively, are assembled to each other, as by placing them face to face, as shown in Figure 5, thereby bringing the two clamping rings I6 and 9 into engagement with each other andalso the frame ring members I4 and 91. The parts are secured together in any suitable way as by screws, bolts, or the like, and the parts are also so pro portioned and shaped that the optical axis of the lens 54 is coincident with that of the lens system as a whole and also so that the lens 5 1 moves lengthwise of that optical axis and without seated in a recess I0'I of a ring frame member I08 generally similar to the ring members already described; the spring support I06 has mounted on it an armature IIO, by way of the nonmag netic ring or spacer III, and armature IIO has a winding IIZ, illustratively thereby energized by alternating current.

The frame ring member I08 has a substantially rectangular recess H3 in which is received the two-part core structure I I4I I5, the latter being provided with a winding I I6 to be energized illustratively with direct current. Spring support I06 is clamped in place by a clamping ring Ill and the resultant lens mounting and moving unit is secured to the preceding unit, back to back, in any suitable way as by screws or bolts (not shown). Here again, the parts are so shaped and dimensioned that the lens 55 has its optical axis coincident with the optical axis of the lens system and so that it moves along that optical axis without tilting.

In each case, also, and preferably, the effective magnetic axis of the electromagnetic means is coincident with the optical axis of its lens or lens group and hence with'the optical axis of the lens system.

The resultant lens system, with its components individually movable, may now be operated, during exposure of the sensitized camera element, in accordance with the theory and explanation contained in the said Dieterich Patent 1,927,925 with respect to its Figures 2, 3 and 4, and in carrying out such operation in accordance with certain features of my invention, I may and preferably do energize the three field windings 9|, I03 and H6 with direct current, and energize the armature windings 64, I04 and II 2 with an alternating current, so determining the directions of their respective fields, however, as to cause lenses or lens groups 53 and 55 to move in substantial synchronism and to cause lens or lens group 54 to have its movements out of phase with the synchronous movements of the lenses 53 and 55.

Where the assemblages of lenses 53 and 55 are mechanically the same and the assemblage of lens 54 is mechanically reversed with respect to them, the above described out-of-phase movement of lens 54 may be achieved by energizing all of the armature windings 64, I04 and I I2 electrically in phase or in the same direction and by connecting the field windings I03 and H6 in parallel, and in such a way that their respective fluxes pass or act in the same direction relative to their respective armatures. Were the assemblage of lens 54 not mechancially reversed relative to the others, th out-of-phas movement is achieved by reversing the connections of one of the windings of the assemblage of lens 54. Accordingly, one half cycle, lenses 53 and 55 move, say to the left and substantially as a unit, while lens 54 moves to the right, and during the next half cycle of the alternating current, these lenses move in respectively reversed directions.

Therefore, change in focus and hence change in the position of the plane of sharpness through the scene is effected but accompanied by maintenance of the size of the in-focus and out-offocus images on "the sensitized camera element 35, the movement of lens 54 being such as to rectify the change in size of images caused by the shifting of lenses 53 and 55. During alternate half cycles, therefore, successive and relative shifts in the three lens groups 53, 54 and 55 take place as are sh'own diagrammatically in Figures 2, 3 and 4 of the said Dieterich patent, relative shifts in relatively reversed directions taking place during intervening cycles. The manner of control, adjustment, or regulation, of the lenses or lens groups of Figure 5 and of their movements are carried on as is later described in detail.

Considering further the structural arrangements shown in Figure 5, it is to be noted that the resultant unitary assembly of the several sub-units is secured in any suitable manner to the rotatable lens-carrying plate 4| (see also Figures 1-3) and preferably enclosed also in the casing 50, and where it is desiredto vary the amount of light with change in focus, as taught in the said Dieterich patent, I prefer to employ a variable aperture or diaphragm comprising four plate members I20, I2I, I22 and I23 (see now Figure 11), shiftable to vary the size of the rectangular opening formed thereby and through which l ght rays from the scene or object to be photographed pass on their way to the lens system of Figure 5. These plate members, arranged in opposed pairs, as shown in Figure 11, are carried by a disk-like mounting plate I24 which, as shown in Figure 5, is interfitted with the righthand end of the assembly unit of lens 55, being secured thereto in any suitable way as by screws, or the like, and preferably also abutting against the clamping ring I IT.

This supporting plate I24 has an aperture alined with the optical axis of the lens system and if des red may have related to it an iris diaphragm for fixing theb-ase value of light from the scene or object and with respect to which base value of light variations are to be achieved during the changes in focus.

Accordingly, the mounting plate I24 is recessed as at I25 (Figure 5) and in that recess ismounted any suitable or known form of iris diaphragm I26 provided with any suitable means, indicated at I 21, for adjusting or setting it. And to the right of the iris diaphragm I26 are positioned the light-varying plate members I20, I2I, I22 and I23. The latter are movably mounted, as is later described in detail, on the front of the plate I24 sothat opposed pairs of these plates may be moved toward or away from each other (Figure 11). To each plate member is related and connected a plate-moving and controlling means or unit, as indicated at I30, I3I, I32 and I33, and

inasmuch as these four units are of identical construction, it will sufllce to describe only one of them in detail.

Accordingly, and still referring to Figure 11, the unit I30 comprises a two-part rectangular frame MI and I42 secured together as by screws I43 but having clamped therebetween two op-. posed end portions of a sheet'material spring support I44, preferably corrugated and which is to function substantially like members 41 of Figures 9 and 10. The rectangular spring support I44 carries a small ring-shaped or annular armature I45 provided withialcoil I46 and the armature I45 projects into air gaps formed in and by a two-part field or core structure I41 and I48. Field or core part I4! is constructed and shaped substantially like the part 80 of Figures 7 and 8 and is made of a magnetic material like Permalloy, being fitted in between, and secured by screws I50 to, opposed downwardly directed extensions I42 of the non-magnetic frame part I 42. The core part I4'I has extending upwardly from its bottom portion the hollow ring-shaped core part I48, the latter being in, general like the core part 8I, for example, of Figure 5, and about the core part I48 is a winding I5I which is energized by direct current in which the armature winding I46 is energized by alternating current.

The frame parts l4I--|42 are supported for sliding movement in suitable ways I52 provided on or in the plate member I24 and the latter has a lug or projecting portion I53 through which is threaded the thumb screw I54, the latter being provided preferably with micrometer type of calibrations to facilitate speed and accuracy of setting. The lower end of the thumb screw is in rotatable connection with a cross-piece I55 bridged across the frame part MI and accordingly, when the thumb screw I54 is manually rotated, the frame I4I-I42 with the parts carried thereby is correspondingly moved up or down, as viewed in Figure 11, along the guiding ways I52, suitable springs I56 being provided to take up any lost motion or back lash.

Such movement of adjustment is transmitted to the diaphragm plate I20 by a connecting link I57 whose upper end is anchored as by a screw I58 to the exact center of the spring support I44.

But the corrugated spring support I44 may and does partake of movement under the coaction of the two windings I46 and I5I and their coacting magnetic circuits or parts and the movements of the spring support I44, communicated to the diaphragm plate I20, may be coordinated in any desired way with the movement of the lens system or any component part of the latter, all as will be lated described in detail.

The control units I3I, I32 and I33 (Figure 11) of the diaphragm plates I2I, I22 and I23, respectively, are, as above-mentioned, of identical construction as is also shown in Figure 11, as to which it need at this point only be noted that the respective field and armature windings thereof are indicated by the reference characters I6 I, I 62 and I63 forthe field windings and I64, I 65 and. I66 for the armature windings. The various fieldwindings and armature windings may be connected in parallel or series; after initially setting or determining (as by the thumbscrews I54) the average or mean size of aperture formed by the four diaphragm plates, the latter are moved toward or away from each other synchronously, the amount of light passed therethrough correspondingly varied, and suitably coordinated with -changes in focal length brought about b the lens system as above described.

In the casing part 46 (Figures 1 and 3) and exposed to the aperture 41 (Figure 3) is mounted a photoelectric cell I and the latter and associated circuit and control and indicating means I preferably arrange to facilitate an initial setting or testing of the action of the lens system and related parts above described. Due to the arrangement, illustratively as by sliding the camera casing 30 along its ways 31, 38, as already above described, the sensitized camera element 35 can be moved out of juxtaposition to the lens system and the photoelectric cell I10 substituted for it, for purposes later described in detail.

The above described electromagnetic and elec trical parts or features of my invention are electrically interrelated by circuit arrangements of which Figure 12 depicts an illustrative embodiment; in Figure 12 the various windings coacting to effect movement of the various lenses and diaphragm parts are diagrammatically indicated and identified by their respective reference characters. Preferably I utilize a suitable source I'II of alternating current, for example such as is commercially available, usually of 60- cycles and I10-volts. For reasons later set forth I prefer to provide also appropriate means for varying or changing the frequency and at I12 I have diagrammatically indicated what I shall term a frequency changer. This may comprise any suitable means or apparatus such as, for example, a motor-driven alternator, the speed of drive and hence the frequency of output of which may be varied or changed throughout a suitable range. From the frequency changer I12, conductors I13 and I14 lead through a suitable voltage-regulator I15 to a step-down transformer I16; the output of the transformer I16 is passed through a filter I11 and from thence conductors lead to the armature coils 64, I04 and H2, connecting the latter in parallel so as to permit the insertion of their respective branch circuits of current-varying or control devices, illustratively in the form of rheostats I18, I19 and I60, respectively, and of indicating meters, preferably volt meters, I6l, I82 and I83, respectively. Thereby the armature windings may be independently energized and their respective energizations determined or varied as circumstances require, and also visually indicated by the meters.

The field windings 9I, I03 and H6, of the various lens units, are supplied, as above noted, with direct current, By way of conductors I64 and I85, alternating current energy from the source I1I is supplied to a rectifier diagrammatically indicated at I86; this rectifier may be of any suitable type, is preferably a full wave rectifier, and preferably, also, includes means, such as an input stepdown transformer, for reducing the voltage of the direct current output of the rectifier.

Suitable conductors connect the field windings 9|, I03 and H6 to the direct current output of the rectifier I86 and illustratively they are connected in series through a current-controlling device, such as a rheostat I81, and also through an indicating device or meter I 88, such as an ammeter for indicating the energization of these windings.

Suitable switches I89 and I90 may be provided to open or close the circuits of the respective field and armature windings. In analogous manner the field windings I5I, I6I, I62 and I63 of the light-controlling devices of Figure 11 are connected in series and to the direct current source, such as the output of the rectifier I86;

preferably a suitable current-varying or controlling device, such as a rheostat I9I and a switch I92 are provided in this circuit. Likewise, also, the armature windings I46, I64, I65 and I66 of the light-controlling means of Figure 11 are connected in parallel, as indicated, and supplied with low voltage, from the circuit I13-I14, by means of a transformer I93 in whose primary circuit is included a suitable voltage regulator 194 and a switch I95 and in whose secondary circuit is included a suitable current-varying device such as a variable resistance I96.

Accordingly, with all'of the circuits closedand appropriately adjusted, the various lenses or lens groups, such as the lenses 53, 54 and 55, are set into movement or oscillation at a frequency or periodicity which is a function of the frequency of the alternating current energizing the armature windings, and as set forth above lenses or lens groups 53 and 55 move in synchronism and in the same direction but lens or lens group 54, while moving synchronously with the other lenses, moves in opposite direction with respect to the latter, for reasons already set forth above.

The diaphragm plates 120, I2I, I22 and I23, move in synchronism, opposite or opposed plates moving toward each other at the same time during one half cycle and away from each other during the succeeding half cycle, thereby restricting and enlarging the aperture, and doing so synchronously with the movements of the lenses of the lens system inasmuch as their armature windings I46, I64, I65 and I66 (Figure 12) are energized in phase by the same frequency of alternating current energy as are the armature windings of the lens system.

As for the photoelectric cell I10, that is shown diagrammatically in Figure 12 and its electrodes are included in a circuit in which is included a suitable source of potential 200 which is preferably derived, as by conductors 20I and 202, through a switch 203 from the principal or primary source I1I, the abovementioncd source 200 comprising any suitable device, well known in the art, for providing in the circuit of the photoelectric tube I10 'a suitable potential. In the output circuit'of the tube I10 is included a suit able measuring or indicating device 204 that is preferably of a sensitive and precision type, such as a vacuum tube type of A. C. voltmeter, for indicating current fiow in the circuit of the photoelectric cell and also variations in such flow; this indicating means may, if desired, include an amplifier 205, and preferably the circuit of the light sensitive cell I10 has associated with it also an electrical filter 206.

The various control and indicating devices and circuits, excepting for the field and armature windings, the photoelectric cell, and its amplifier, may be assembled and compacted in a portable casing 201, as indicated in Figure 4, suitable cables 208 and 209 leading certain of the circuits to the field and armature windings and to the photoelectric cell and its amplifier and a suitable cable 2I0 leading other conductors to, for example, a connector plug 2 by which con nection may be made to a suitable source of primary energy, such as the source I1I of Figure 12. Preferably, the amplifier 205 is mounted in the casing part 46 that contains the photoelectric 'cell.

The various manually operable parts of the circuit arrangement of Figure 12, such as rheostats, switches, or the like, may be exposed from the cabinet 201 (Figure 4) in any suitable manher for convenient manual operation, and the various indicating devices or meters may likewise be so related to the cabinet 201 as to be readily observable by the operator, all as is diagrammatically or fragmentarily indicated in Figure 4. Thus, the control equipment and accessories can be conveniently, associated with the camera itself and meet such requirements of the latter as mobility, portability, or the like.

.After having closed the various circuits to make them effective, thus setting the lens or lenses and the light-controlling means of Figure 11 (where the latter is desired to be employed) into movement or oscillation, the camera casing 30 is shifted to bring the aperture 41 (Figure 3) and hence the light-sensitive cell "0 in alinement with the optical axis of the system, whereupon a current flow becomes eifective in the circuit of the cell I10 and a corresponding potential is indicated by the voltmeter indicator 204 (Figure 12) To achieve the desired setting or range of movement of the movable lens or lenses for a given condition of light on the scene or object to be photographed, the movement of the light-controlling means of Figure 11 is first halted, as by opening the switch I95 of Figure 12, and the iris diaphragm I26 set or adjusted to determine the means or average value of light that is to pass through the lens system suitable for or appropriate to the particular character of the scene itself.

If the amplitude or distance of travel of each of the synchronously moving lenses or lens groups is not properly correlated with respect to the amplitude or travel of the other lens or lens groups, the images projected upon the photoelectric cell will in effect be blurred, in that out-of-focus images do not register concentrically with in-* focus images and thus the effective light transmitted to the photo cell "0 is in quantity different from the light which would reach it if the in-focus and out-of-focus images were of the same size and hence registered, as would be the case if the movements of the lenses relative to each other or to the film plane (in which the light-sensitive element of the photo cell I'I0 finds itself) were properly correlated. Accordingly, the indicator 200 (Figure 12) gives an indication of this inappropriate condition and since the movement of the lens or lenses is periodic, the indicator 204 also registers the fluctuating light density in terms of alternating current, the electrical filter 206 being switched into its circuit by its switch 260 during these operations and acting as is later described in greater detail.

Accordingly, after again closing switch I95 suitable adjustments are made of the respective currents flowing to the armature windings 64, I04 and I I2, by manipulating their respective rheostats I18, I19 and I80, all with respect to a given or initial suitable setting of the variable resistance I81 that determines the current flow to the field windings.

ture windings are energized, illustratively a frequency of 60 cycles; but also taking part in these actions is the filter 206 which is connected in parallel by switch 260 in the output circuit of the photoelectric cell amplifier and which is so proportioned or adjusted as to suppress all fre quencies other than the frequency of the current in synchronism. with which the armatures and their respective lenses are vibrating or oscillating. Thereby, also, oscillations or variations in the normal light reaching the image of film plane, and corresponding to the noise level" or frequency of the normal light, are suppressed and prevented from causing the indicator 204 to give false indications. Accordingly, the indicator 204 is made to give a true indication of the light action of the lens system, foreign disturbancesor frequencies being thus dependably eliminated.

As soon, therefore, as such adjustments have been made of the currents energizing the armature windings, one with respect to the other, as cause the indicator 200 to reach a minimum or near-zero reading, the lens system will have been adjusted properly, both as to the individual ranges of movement of the individual lenses and as to the relative movements between the lenses, the-steady or minimum indication of the indicator 204 indicating that the in-focus and out-of-focusimages of the scene or'object are, in the image plane, of thesame size and in registry with one another, a condition which corresponds to substantially no variation in light intensity. Or, in any case, the adjustments are made so as to achieve a minimum, if not an absolute zero, indication or fluctuation of the indicator 204 to correspond to substantial coincidence of in-focus and out-of-focus images in the image plane.

The resultant action of the lens system is one coresponding to that described in Dieterich Pat ent 1,927,925 with respect to Figures 2, 3 and 4 thereof.

In practicing the art of photography, scenes of different depths are, of course, met with. For example, an indoor scene generally is of less depth or distance from the foreground to the background than is an outdoor scene that. includes or sweeps a substantial range of terrain. By way of my system I may quickly and easily set the range of movement of the lens or lenses so that the range of change of focus corresponds very closely to the depth of the particular scene to be photographed. For example, if the scene is of small depth, such as an indoor scene, the energization of the armature windings of lenses 5.3 and 55 (Figure 5) is first so adjusted that the range of change of focus of the lens system is such that the plane of sharpness moves from a point near the camera toa point (or plane) corresponding substantially to'the background or wall of the scene and thereafter the energization of the armature winding of lens 54 is adjusted or set, in the manner above described and with reference to the indicator 204, to bring the in-focus and out-of-focus images to the same size and in registry with each other.

If the scene is one of very great depth, such as an outdoor scene that includes a remote landscape, for example, then the energization of armature windings of lenses 53 and 55 is so set that the plane of sharpness of the lens system moves from a point or plane near the camera to a point or plane as remote as the remotest point in the scene, and then the energization of armature winding of lens 54 is set, in the manner above described, again to bring the in-focus and outof-focus images to the same size and in registry with each other.

Thus, the lens system can be quickly and with precision suited to any particular range of change of focus called for by the depth of the particular scene or object to be photographed. Thereby the maximum efliciency of the lens system is brought to bear during each exposure and superior light action on the film or sensitized camera element achieved. 1

If desired, the control apparatus, such as that shown in Figure 12, may be calibrated with respect to each of the adjusting devices, such as the various rheostats or variable resistances, and also with respect to the various indicators or meters. For example, the voltmeters I8I, I82 and IE3 (Figure 12) may be calibrated both in volts and in focal distances or depths of scene for given indications of the ammeter I88 in the circuit of the field windings; if this is done, then corresponding rheostats I18, I19, I89 and I81 may be at least preliminarily set to give the desired indications of the voltmeters and ammeter in terms of focal distances or depth of scene, and the photoelectric cell arrangement above described utilized as a final or precision checking of the adjustments thus given.

With the lens movements properly set or determined, the light-varying or controlling means, such as the diaphragm plates I29, I2], I22 and I 23 of Figures 5 and 11, may be set into action as by closing switches I95 and I92 (Figure 12) and rheostats I 9| and I96 adjusted to give the desired range of change of light during each exposure; when these diaphragm plates are thus set into action they move in synchronism with the movable lens or lenses of the lens system for all of the armature windings are energized by the same frequency of alternating current. The resultant variations in light upon the photoelectric cell I10 are in the nature of fluctuations of a frequency corresponding to the energizing alternating current employed and the indicator 204 in the circuit of the photoelectric cell I'III may be used (it may also be correspondingly calibrated) to determine the respective settings of the variable resistances I9I and I95 and thereby to determine with precision the range of changeof light intensity from the average value set by the iris diaphragm I26. Here again, a suitable indicating device 220, illustratively taking the form of an ammeter, and an indicating device 22I, illustratively taking the form of a voltmeter, may be used (and also calibrated in terms of light variation, etc.) to indicate the settings of the energization of the field windings I5I, I6I, I62, I53 and of the armature windings I46, I64, I65- and I 66, respectively.

Though the light-varying diaphragm plates move in synchronism with the movable lens or lenses, the armature windings of the former are preferably energized with alternating current in such a direction that the diaphragm plates progressively open as the lens system moves the plane of sharpness from a point near the camera to a point remote from the camera.

If. desired, the results of the settings thus achieved may be visually checked or such visual checking may be achieved during the procedure of setting and testing by shifting the camera casing 30 (Figures 1 and'2) to such a position that neither the film nor the photoelectric cell I10 is juxtaposed to the lens system but that the latter is accessible from its rear to permit the operator to sight therethrough and see with the naked eye what the action of the system is.

In Figures 13 and 14 I have shown a modified form of lens system and operating control therefor in which the lens system per se takes the form of that described in Dieterich Patent 1,927,- 925 with respect to Figures 9, 10, 11 and 12 or of those described in Dieterich Patent 2,025,731. Thus, for example, in Figure 13 herein lenses 230, 23I, 232 and 233 may correspond, respectively, in construction and action, to lenses 2B, 21, 28 and 29 of Figures 2 and 5 of Dieterich Patent 2,025, 731, or to lenses 226, 221, 228 and 229 of Figure 9 of the said Dieterich patent, or to lenses 4, 3, 2 and] of Figure 9-12 of Dieterich Patent 1,927,925; accordingly, reference to the said patents may be made for details of the construction and action thereof, and hence those matters need not be dealt with in detail herein.

Accordingly, and again referring to Figure 13 herein, which may be considered to be a sectional view as along the line 5-5 of Figures 1 and 3 herein, where it is desired to embody in the camera this modified and preferred embodiment of my invention, the lens system will again be seen to be mounted on the lens-carrying plate H, the latter being shown in Figure 13 in such a position that the lens system and related parts are shown juxtaposed to the diagrammatically indicated film or sensitized photographic element 35, the shutter 52 and the aperture 5|, all as was described in connection with Figure 5. Where the film 35 is a motion picture film, its

intermittent or step-by-step movement to present successive frames for exposure may be achieved by any suitable mechanism such, for example, as that described above in connection with Figure 5*. Where in Figure 5 the lens system as a whole was arranged to be moved and one of the lenses moved relative thereto, in the arrangement of Figure 13, as in the said Dieterich patents just mentioned, lenses 230, 232 and 233 are stationary and lens 23I is movable. Lenses 232 and 233 may bemounted in any suit able manner (see Figure 9 of Dieterich Patent 2,025,731), in a sleeve-like extension 234 of a stationary mounting plate 235 adapted to rest against and be secured to the rotatable lens plate 4|.

The movable lens 23I is mounted for movement and provided with a moving means therefor substantially identical with the mountings and moving means of any one of the lenses as described in connection with Figure 5, for example like those of lens 53 of that figure. The construction and action of the detailed parts therefore need not be described again, but it might be pointed out that the movable lens 23I is carried in a sleeve-like member 236 in turn secured to the sheet-like flexible or resilient or spring support 231; the latter carries a ring-shaped armature '238 secured thereto and spaced therefrom by a non-magnetic spacer ring 239. Armature 238 carries an energizing winding 249 and with the armature 238 is positioned in the annular-like air gap between the field core structure 24I--242, the latter corresponding, for example, to the parts and 8|, respectively, of Figure 5. The field core structure is energized by a field winding 243 preferably .to produce a uni-directional magnetic flux in the air gap, armature winding 24!] being energized by alternating current of appropriate frequency.

The field core structure is carried in a ringshaped member 244 secured in any suitable man-- ner to the lens supporting plate 235 and it has an annular or stepped recess 245 in which is seated the outer peripheral portion of the spring support 231, the latter being clamped in the said recess 245 by a clamping ring 246 held and pressed toward the ring support 244 in any suitable manner.

With this mounting of the movable lens 23I and energization of the armature and field windings in the manner above-described in connection with Figure 5, the lens 23!,m'ay be vibrated or oscillated at the frequency of the alternating current energizing the armature winding 240; such movement of the lens 23I is, of course, relative to the stationary lenses 232 and 233 and also to lens 230, the latter being suitably secured in a sleeve-like mounting 241 carried by or suitably secured to a disk-like mounting or supporting member 248 which rests against the clamping ring 246 and against the ring support 244, being secured to the latter in any suitable way. Of course, all of these lens supports and mountings are so shaped and assembled together and held so assembled that the optical axes of the individual lenses are coincident and hence coincide with the optical axis of the lens system. For reasons fully explained in connection with Figure 5, the movement of the movable lens 23I is such that the lens does not tilt and hence maintains its own optical axis always in coincidence with the optical axis of the lens'system, throughout its range of movement.

Fitted up against the lens mounting or supporting member 248 is a frame ring 250 shaped at its left-hand face to mate with the supporting member 248, broadly in a manner similar to the way in which the mounting plate I24 (Figure is alined with and-related to the ring support I08; the mounting plate 250 of Figure 13 is otherwise similar in construction to mounting plate I24 of Figure 5, having, therefore, an iris diaphragm I26 with a suitable manual control I21 and likewise having the movable plate members I20, I2I, I22 and I23 with their associated moving and control means, all as described above in connection with Figures 5 and 11 and 12, these parts being therefore indicated, without further description, in Figures 13 and 14 by similar reference characters.

The lens system of Figure 13 and related parts may be related to or enclosed in a suitable casing 50 similar in general to the casing 50 of Figure 5.

In Figure 14 is shown diagrammatically the circuit arrangement preferably employed in operating the preferred embodiment of my invention, namely, that of Figure 13, and since many of the parts of Figure 12 are duplicated in Figure 14 and identified by the same reference character, the arrangement will in general be clear in View of what has been set forth in connection with Figure 12. vIt will be noted that the system is substantially the same as that of Figure 12 excepting that, since it is possible by way of the arrangement of Figure 13, to employ only a single movable lens, Figure 14 shows only a single field winding 2 33 to be energized from the direct current source and a single alternating current armature winding 2&0 to be energized from the source of alternating current, instead of three field windings and threearmatin'e windings, as in Figure 12. The adjusting and testing means of Figure 14 are the same as those employed in Figure 12.

If. the movable lens iii of Figure 13 is vibrated or oscillated throughout an appropriate range and relative to the remaining lenses, all as described in the aforesaid Dieterich patents, as above-mentioned, the plane of sharpness is shifted back and forth from a point near the lens to a point remote from the lens while at the same time in-focus and out-of-focus images are maintained at the same size and inregistry, in accordance with the said Dieterich patents.

In setting the system, switches I95 and I92 are first opened so that the light-controlling or varying diaphragm plates I2.0,..I2I, etc. are motionless, and iris diaphragm I26 is set by its control I21 to determine the mean or average aperture through which light is to be allowed to pass to the lens system from the scene or object to be photographed, the diaphragm plate moving units (see Figure 11) being set as by the adjusting screws I54 to give an average size of aperture commensurate with the aperture set or determined by the iris diaphragm I26. The procedure thus far is similar to that pursued in connectionwith the arrangement of Figure 5.

Next, the camera casing 30 of Figures 1, 2 and 3 is shifted so as to bring the photoelectric cell I in juxtaposition to the lens system and hence on the optical axis of the latter, whereupon switch I90 (Figure 14) may now be closed to energize the field winding 243 with direct current and then switch I89 closed to energize the armature winding 240 with the alternating current, the electromagnetic system thus setting the movable lens 23I into oscillating motion.

The control or variable resistance element I81 may now be set to a value as indicated by the ammeter I 88 either in current intensity or by way of, other indication for which the instrument may be calibrated, and then the control or resistance element I18 is progressively shifted to increase correspondingly the alternating current energizing the armature winding 240. The alternating energizing current is thus slowly increased until the indicator 204 in the circuit of the photoelectric cell gives a maximum indication, the latter corresponding to proper setting or determination of the range of movement of the movablelens 23I (Figure 13). This maximum indication of the meter or instrument 204 occurs at those points in the adjustments or settings of the control elements I18 and i8l corresponding to which the range of movement of the lens 23I with re spect to the remaining or stationary lenses is appropriate to bring all of the in-focus and out-offocus images to equality of size and also to registry with one another for the scene or object being photographed, since diffusion of light in the image plane and also halations, corresponding to what would be visual blurring or out-of-focus effects, are eliminated. During this time the harmonic filter 206 is cut out of the amplifier circuit of the photoelectric cell by means of its switch diagrammatically indicated at 2G0 in Fig ure 14.

Next, the light-controlling diaphragm plates I20, I2I, M2 and M3 (Figures 11 and 13), having already been approximately set, may now be precisely set by manipulating the thumbscrews I53,

Iii

In the firstplace, the iris diaphragm is set to make sure that sumcient light falls upon the sensitized camera element or film as is necessary to photograph the most distant objects in the particular scene, this adjustment being preferably made with the diaphragm plates I20, l2l, etc., motionless, as by opening switch l95. Here again, the indicator 264 may be appropriately calibrated in terms, of suitable factors, such as the distance of the most remote points in the scene or object.

Having thus achieved a precise settingof. the iris diaphragm, for the particular conditions to be met, the diaphragm plates I20, l2l, etc., are again set in motion and rheostats or control elements Ni and I96 (Figure 14) are manipulated one with respect to the other until the indicator or meter 264 reaches a maximum, such as indication corresponding to proper or optimum positioning of these movable elements.

Thereafter, the lens 23l is set in motion and thus the entire regulating and moving system is in action and now switch 260 of the harmonic filter 206 is actuated to bring the filter into the circuit and the above-mentioned adjustments of the diaphragm plates [20, I2 I etc. is now checked. If the indicator 204 now indicates a minimum, determined by way of manipulating either or both of rheostats [9| and I96, the system is in appropriate setting and is ready for operation. The photographing of the scene or object may now he proceeded with.

In connection with the lens system of Figures 5 and 12, I described above how the lens-moving system may be set to permit selection at will of any desired range of change of focus and in accordance with certain other features of my invention, I may achieve, with the lens system of Figure 13 and its control system of Figure 14 a similar selection at will of the particular range in the scene throughout which the focus or plane of sharpness is to be changed or shifted. This I achieve by mounting on the yieldable or spring support 231 (Figure 13) which carries the movable lens 23l, an electromagnet in the form of a ring-shaped or annular armature or field core 26l and provide it with a winding 262. The ring or frame support 244, made of a non-magnetic material, such asbrass, is suitably recessed as at 244 to accommodate the electromagnet 26I--262 and also to accommodate a coacting electromagnet in the form of a ring or annular armature or core 263 provided with a winding 264.

These two electromagnets are thus appropriately juxtaposed to each other for appropriate coaction and in Figure 14 they are diagrammatically indicated by their windings 262 and 264, being shown connected in parallel through a control means, such as a rheostat 265, an indicating device, such as an ammeter 286, and a switch 261, to the source of direct current, such as the rectifier I86. One of these coils, such as coil or winding 262, is connected in this circuit through a reversing switch 268.

Accordingly, if these two electromagnets are energized so as to oppose to each other like poles, electromagnet 26l--262 (Figure 13) is repelled by the stationary electromagnet 263264 and hence the spring mounting or support provided by the spring supporting member 231 is biased toward the right, as viewed in Figure 13, and hence the movable lens 23l is made to assume a diiferent normal and neutral position than it did theretofore. Accordingly, the actual range throughout.

which the lens 2! is subsequently oscillated under the control of windings 243 and 240 above described is shifted to the right and the lens system, instead of changing the focus from a point near the camera to a point infinitely remote from the camera (as it would if it operated throughout its normal or complete movability of the movable lens) now changes the focus throughout a smaller range but at one end of its original or complete range of movement. By causing the two electromagnets that thus bias the spring support 231 to have opposite polarities rather than like polarities, as by operating the switch 268 (Figure 14) to reverse the current in winding 262, the two electromagnets 26I262 and 263-264 (Figure 13) now set up a force of attraction rather than repulsion and spring support 231 becomes biased toward the left; thereby a range of change of focus comprising only a portion at the other end of the original or complete range of change takes place.

In either case, of course, the intensity of energization of the biasing magnet windings and the intensity of energization of the windings 240 and 243 of the lens-moving magnet are appropriately correlated one with respect to the other and preferably by means of the photo cell circuit and related apparatus, all as was above described in detail.

Thus, the lens system of Figure 13 may be made to concentrate its unique actions of change in focus without change in size of image, throughout any desired depth of field whether that depth of field is near the camera or in the more remote portion or portions of the scene or object. Scenes or portions of scenes of smaller depth that require equal movements of the movable lens 23l to either side of its normal neutral optical position with respect to the remaining lenses may be photographed by open circuiting the biasing magnet windings 262 and 264, as by opening switch 261, and appropriately adjusting rheostats I18 and I81 give the movable lens 23l a smaller range of oscillation or of movement, thereby concentrating the action of the lens system in changing focus while maintaining size of in-focus and outof-focus images, throughout a corresponding depth of scene positioned at a point intermediate of nearness to and remoteness from the camera. In any such case, the indicating instruments l8l, I88 and 266 may be calibrated in appropriate terms to facilitate selection at will of the range of action of the lens system and the location of that desired range of action within the entire available capacity or range of action of the lens and control system.

In connection with both illustrative embodiments of my invention, I have indicated by way of illustration that I may employ a GO-cycle alternating current and that, therefore, the lens movements are such that the lens or lenses partake of sixty complete oscillations per second, each oscillation comprising two strokes of movement in opposite directions. Where my invention is embodied in a motion picture camera I need not On the other hand and if it is desired to substantially synchronize lens movement with frame exposure, the frequency changer I12 of Figure 14 is brought into action to change the frequency of the system to match, or become a multiple of, the frequency of film-frame exposure; where the latter is twenty-four per second, the output of the frequency changer I12 may be, for example, twenty-four, forty-eight, or the like, cycles per second. If such a change in frequency is resorted to, then the various filters above described are, of course, correspondingly adjusted to filter out or suppress frequencies above the selected frequency.

However, I have discovered that with the aid of my lens control and lens-moving system, I am enabled materially, if not entirely, to avoid so-called halation, caused, as is known, by reflection or refraction of light on or within the film itself. In that connection and referring to Figures 12 and 14, I energize the armature winding or windings of the movable parts with an alternating current of a frequency comparatively high in order thereby to cause the movable lens or the movable lenses (as well as the light-varying diaphragm plates, where those are employed) to move at faster rate of oscillation and to partake of several cycles of movement during each exposure. The efiect of that action is to eclipse at high frequency the images projected upon the exposed camera element or film, bearing in mind that, as the lens system shifts the focus from one plane of sharpness to another, light from the object or points within that one plane of sharpness is, in effect, cut off and light coming from the object or points in the other plane of sharpness is what is directed onto the film. The higher the frequency of this eclipsing action, the less dense will be the light striking the film per cycle of the frequency of eclipsing.

Accordingly, by materially increasing the frequency of oscillation of the movable lens of Fig ure 13 or of the movable lens of Figure 5, I am enabled to achieve a high frequency of effective eclipsing action with corresponding lessening of density of light per eclipsing cycle; with the den.-

sity of the light thus diminshed, and with the above-mentioned halation efiects substantially proportional to the density of the light striking the film, I am thus enabled materially to minimize or negative halation effects and hence the recording thereof. Accordingly, it is desirable to operate the system at a frequency that is a substantial multiple of the illustrative sixty cycles above set forth. And also, it is to be noted that in such case the various filters above-mentioned are provided with suitable means for adjusting them to suppress frequencies higher than thesele-cted or operating frequency. Such factors as the distribution of mass of vibrating elements, the stiffness or resiliency of spring supports, the electrical impedance of the various alternating cuirent circuits may be modified, changed or readjusted in any suitable way, if necessary, to suit the new condition or conditions of frequency of alternating current employed.

As earlier above noted, the source of variable or selectable frequency, diagrammatically indicated in Figures l2 and 14 at H2, may take any suitable form, but I might note that a convenient and preferred form of apparatus 512 comprises any. ap propriate so-called oscillator made up of a suit" able electronic conduction tube or means with appropriate circuits, preferably variable and preferably including an amplifier, to produce a source of alternating potential or current of selectable frequency. With such a preferred form of apparatus a relatively wide range of change of frequency may be made ready and conveniently available without detracting from the various other numerous advantages of the system and apparatus.

In this connection, the action of the lens system may be further modified to achieve certain further unique actions and results. For example, by selecting a high frequency, thereby to achieve lens oscillation at correspondingly high frequency, the effect of the lens system is to record upon the sensitized camera element or film a resultant image that is sharper than the image recorded where a lower frequency of energization and hence a lower frequency of lens oscillation is made effective. Accordingly, I make it possible to vary the sharpness of recording according to practical requirements and where motion picture photography is involved the operator may thus, by appropriately changing or selecting the frequency of energization, speedily and quickly determine the lens action to suit the technique, style or artistry desired for the particular scene, person, or object being photographed.

The photoelectric cell and its associated testing circuits may, of course, be utilized from time to time to check the initially selected settings or selection of action of the various parts, though it might be pointed out that, with the inclusion in the circuit arrangements of the voltage regulators and filters such as the regulator I15 and filter H! of Figures 12 and 14, such subsequent checking need not be resorted to inasmuch as these parts insure that the action of the lens system and its various controls, when once selectively set as described above, remains invariable under normal operating conditions; the regulator insures the absence of voltage fluctuations and in coaction with the filter insures a steadiness of power flow that maintains steadfast the initially selected operating conditions. The filter, moreover, insures a suppression of distortion of wave shapeandthuscontributes toward insuring steadiness and constancy of action. The foregoing assumes, of course, normal operating conditions of temperature of the various electrical parts, particularly the field windings and armature coils of the various moving parts.

A particular advantage is achievable by way of the system of Figure 13. Should the frequency of oscillation of the movable lens or lens group bring about sound effects, due principally to the frequency of oscillation entering well into the range of audio frequencies, such sound effects may be negatived in any suitable way; in that connection and as appears better in Figure 13, use may be made of the structural features whereby the space in which the moving parts, such as the lens 231 and the spring support 231, are totally enclosed as by the member 235 with the lenses 232 and 233 carried by it, and by the member 248 and the lens 238 carried by it, and if desired the resultant sealed space may be evacuated in any suitable manner, thus insuring the absence of sound-transmitting effects.

With respect to both illustrative embodiments, namely those of Figures 5 and is is to be noted that any such sound effects ermore substantially or entirely eliminated due to the features of construction embodied in the spring lens mountings, such as those shown in Figures 9 and 10; the disk-like members there shown will be seen, as earlier described, to contain cut away or apertured portions and thereby efiectively diminish or negative the possibility of setting up sound waves through the atmosphere.

These considerations are of interest in connection with the practicing of my invention in the motion picture field or broadcasting where the process of photographing or of image production or reproduction is accompanied by a recording or broadcasting of accompanying sound or sound efiects.

I have earlier above described the casing construction 5% (Figures 1, 2., 5 and 7) as including a cylindrical casing part; the latter may be closed at its right-hand end by certain of the structures already above described in detail, such as the ring mounting plate iii of Figure 5 or the mounting plate 250 of Figure 13; the right-hand ends, how ever, of these mounting members are closed by a casing counterpart structure illustratively in the form of a sheet metal member 210 shaped in any suitable way to closely mate with the exterior of the contour of the ring-like mounting plate and its various lugs or projecting parts, thus to substantially enclose the operating mechanisms carried by the mounting plate. This casing counterpart 210 is provided with an aperture 2', preferably circular, having its axis coincident with the optical axis of the lens or lens system, the aperture 2' being of appropriate size or diameter to pass therethrough suflicient light from the scene or object for appropriate action or control by various of the parts, as already above described. Member 210 thus also functions as a shield for the light-controlling means or units and its exterior may be employed as a mounting plate for various accessories applied to camera and the like for producing various effects, effects such as, for example, are known in the motion picture camera art.

Thus, it will be seen that there has been provided in this invention a photographic method and apparatus in which the various objects hereinbefore noted, together with many thoroughly practical advantages, are successfully achieved. It will be noted that precision of control and action are easily achievable and that a wide range of flexibility or change or selection of action has been made possible; furthermore, it will be seen that the method and apparatus are well adapted to meet the widely varying conditions of practical use.

As man possible embodiments may be made of the mechanical and electrical features of the above invention and as the art herein described might be varied in various parts, all without departing from the scope of the invention, it is to be understood that all matter hereinabove set forth, or shown in the accompanying drawings, is to be interpreted as illustrative and not in a limiting sense.

I claim:

1. In apparatus of the character described, in combination, a lens system having a plurality of lenses axially alined and between which relative axial movement may take place and which are corrected to produce, at the image plane of said system and for a certain range of said relative movement, equality of size and registry of infocus'and out-of-focus images of a scene or object corresponding to a plurality of different planes of sharpness, means mounting said lenses in axial alinement and including means movably mounting at least one lens of said lens system for movement axially to effect said relative axial move ment, said mounting means for said movable lens arraros comprising a yieldable disk-like member having means for securing said lens thereto at its axis and means for peripherally anchoring said disklike member, a source of electromotive force, electromagnetic means energized from said source and including a movable part operatively associated with said disk-like member for causing the latter to yield in a direction transverse to its plane and hence to move said movable lens and means for controlling the conversion of energy from said source of electromotive force by said electromagnetic means into movement of said movable part and to maintain movement thereby of said movable lens within the aforesaid range of relative movement, thereby to cause said lens system to eiTect registry of said in-focus and out-offocus images.

2. In apparatus of the character described, in combination, a lens system having a plurality of lenses axially alined and between which relative k axial movement may take place and which are corrected to produce, at the image plane of said system and for a certain range of said relative movement, equality of size and registry of iii-focus and out-of-focus images of a scene or object corresponding to a plurality of different planes of sharpness, means mounting said lenses in axial alinement and including means movably mounting at least one lens of said lens system for movement axially to effect said relative axial movement, said mounting means for said movable lens comprising a yieldable disk-like member having means for securing said lens thereto at its axis and means for peripherally anchoring said disklike member whereby said movable lens, upon yielding of said disk-like member, moves along the optical axis of said lens system, means producing a unidirectional magnetic field, means producing a periodically varying magnetic field subjected to the influence of said first-mentioned magnetic field, means operatively connecting one of said field-producing means to said disk-like member whereby the latter flexes and the movable lens is moved in accordance with the interaction of said two fields, and means for controlling the interaction of said two fields to achieve movement of said movable lens within such a range of movement relative to the remaining lenses that said in-focus and out-of-focus images are in registry.

3. In apparatus of the character described, in combination, a lens system having a plurality of lenses axial]; alined and between which relative axial movement may take place and which are corrected to produce, at the image plane of said system and for a certain range of said relative movement, equality of size and registry of infocus and out-of-focus images of a scene or object corresponding to a plurality of difl'erent planes of sharpness, means mounting said lenses in axial alinement and including means movably mounting at least one lens of said lens system for move ment axially to effect said relatively axial movement, said mounting means for said movable lens comprising a yieldable disk-like member having means for securing said lens thereto at its axis and means for peripherally anchoring said disklike member whereby said movable lens, upon yielding of said disk-like member, moves along the optical axis of said lens system, said disklike member having operatively connected thereto a ring-like armature with an energizing winding thereon for producing a magnetic field, magnetic-field-producing means coacting with said armature and winding to effect move 

